An Improved PAPR Reduction Algorithm in Cognitive Radio System

Non-continuous orthogonal frequency division multiplexing (NC-OFDM) is an effective data transmission technology in cognitive radio (CR) system with high frequency efficiency and anti selective channel fading property. But as with OFDM systems, NC-OFDM also owns large side lobe power and high peak-to-average power ratio (PAPR), which leads to spectrum leakage of licensed users (LUs) and distortion of signal amplification. In this paper, a joint optimization algorithm is proposed. Multi-choice sequence (MCS) for side lobe suppression and fountain codes for high PAPR reduction are adopted in the algorithm. The simulation results suggest that the new algorithm can reduce the side lobe power radiation and PAPR, finally enhance the overall performance of the system effectively.